Honda K24A

It’s probably no surprise that we’ve gone for a Honda K-Series once again, specifically a K24. This replaces the C-Series V6 that the car originally would have been equipped with. This definitely isn’t one for the purists (yes, we’ve seen the comments on the internet), but the K24 saves over 100kg compared to the C30A, parts are readily available and there’s much more potential as far as tuning is concerned.

Speaking of tuning, we’ve bolted a Rotrex C30-94 supercharger to the K24 to give us the power that we’d like to achieve. The maximum power that this supercharger is roughly capable of achieving is around 450bhp, however, we’ve installed a 35mm restrictor to keep the power down. As we’re competing in Club Enduro and the classes are based on power to weight, we’ll be aiming for 295bhp per tonne which meets the class A regulations so our target power figure will be somewhere around 330bhp.

It’s not as simple as simply bolting a supercharger to your engine and away you go, you will of course need a host of supporting modifications. Here are the upgrades that we’ve chosen:

• Skunk2 Racing drop-in cams
• Genuine Honda 50 degree VTC actuator intake cam gear
• Skunk2 Racing Ultra Series intake manifold
• 4 Piston Racing oil pump
• Circuit Hero drop-in oil sump baffle
• Genuine Honda K20 oil sump
• Grams Performance 355LPH fuel pump (This is the same as a Bosch 044)
• Grams Performance 550cc injectors
• Walbro 255LPH in-tank fuel pump
• Bosch 68mm drive-by-wire throttle body
• K-Tuned fuel pressure regulator
• K-Tuned fuel rail and centre mount gauge
• Custom Swirl Pot
• ICEFAB custom exhaust with Funk Motorsport exhaust blanket

MK7 Golf R DSG

Now for the trick part, we’ve mated the K24 up to a 6-speed DQ250 gearbox. This is the same gearbox found in a Mk7 Volkswagen Golf R, however, we’ve removed the 4WD transfer box as we only want to send power to the rear wheels. You’re probably wondering why we’ve gone down this route as it’s not a very ‘off the shelf solution’ and certainly not a common swap. Well, there’s 2 big reasons. Firstly, the standard K-series gearbox isn’t the most durable when running boost, something that we’ve discovered first hand over the year with Tsuki. Secondly, we wanted a sequential box but as you can imagine, sequential gearboxes are rather costly. However, the DQ250 gearbox will act just like a sequential when paired with the ECU (more on that soon), at a fraction of the cost. Finally, it’s just pretty bloody cool, even if we do say so ourselves.

To help put all that power to the ground, we’ve installed a MFactory helical stage 1 race pack LSD. This differential offers 75% torque biasing which means it can give up to 75% of the torque to the given wheel at any one time.

We used a Super Drivetrain Solution DSG adaption kit which contained the engine to gearbox adapter, flywheel to engine steel adapter, intermediate shaft and bracket, all bearings and seals. If you fancy a setup like this on your K-Series then get in touch with us as we can supply these as required. It’s definitely going to be interesting to hear what the car is going to sound like with this combination!

ECU & Electronics

Making the aforementioned stuff actually work is all possible thanks to our ECU, Syvecs S7. Using this ECU enables us to control both the engine and gearbox together, compute faster and a lot more simpler than using 2 separate ECU’s, so it was a bit of a no brainer really. We’ve gone for a full custom wiring loom too which was supplied to us by Autosport Electronics.

Sitting next to the Syvecs ECU is the AIM PDM32 kit which is a 32 channel advanced power distribution module designed to power a multitude of vehicle circuits, which eliminates the need for traditional fuse boxes and relays. This essentially allows you to run a simplified wiring harness with increased reliability and control functions. We’ll pair this up with an AIM PDM dash, 10 button steering wheel plate and a 12 button keypad.

Misc.

There’s been a tonne of other stuff happening around the car that doesn’t involve the engine or gearbox. At the front of the car we’ve got AP Racing brake master cylinders, one for the front brakes and one for the rear.

We’ve got 2 Davies Craig electronic water pumps to help aid cooling. These are a great alternative to a traditional belt-driven pump as they run directly off the motor meaning a loss in horsepower.

As we’ve removed the original headlights in a bid to save weight, we’ve got a couple of spot lights in the front bumper.

The original dashboard has now been flocked and is back in the car. It obviously needs fitting properly but certainly looks great and will help to reduce glare and reflections from the sun.

An SPA 4 litre mechanical fire extinguisher system has been installed in the passengers footwell to comply with safety regulations. This features 4 nozzles in total, 2 in the car and 2 in the engine, in the event that a fire does happen, the driver can simply pull the cable and it will activate.

It goes without saying how important ABS is so we’ve updated ours from a later spec Honda NSX.

The Yellow Speed Racing 4-point air jack system has now been plumbed in. The valve is installed at the back of the car enabling us to plug in the lance and lift the car up at all four corners.

Finally, we’ve installed the mandatory FIA rain light on the rear bumper using our brand new Tegiwa rain light mounting bracket.

Thanks…

There’s been some long days at Tegiwa HQ getting the car to where it has now. We’d like to give a big shout out to our in-house team of Andy Ford and Connor Sheldon for their hard work. We’ve also had the pleasure of experienced chief mechanic Michael Rawlings, from Paddock Performance, who’s been putting in plenty of hard graft to help build the car. Thanks chaps!

What’s next?

Our Honda NSX is now pretty much on the final stretch of the build. We’ve got a few final touches like plumbing the engine in properly and finishing the electronics, then we can think about mapping! This will be done in-house here at Tegiwa thanks to Ti Motorsport, our sister company which provides a tuning service for a wide range of vehicles. Stay tuned as we bring more updates in due course.

Air Jacks

The first task that Andy was tasked with was fabricating some custom air jack mounts both front and rear. As the Honda NSX chassis is aluminium there’s a little more worked involved than what would be required to other cars. These mounts will accommodate a Yellow Speed Racing 4-point air jack system so we can quickly lift the car into the air during pit stops. The craftsmanship that has gone into making these is second to none as you can see from the pictures below.

Seat Mount, Bumper Mounts, Splitter Frame & Bash Bar

A seat mount was then made so we could mount our Cobra Ultralite carbon fibre bucket seat in the desired position with enough clearance for the roll cage. This was followed by front bumper mountings, a splitter frame and a tubular front bash bar.

Cooling Pack

Next up, a cooling pack consisting of large custom ICEFAB radiators and full front end ducting. As you can see this enormous front scoop that sits neatly behind the front bumper is going to draw in as much air as possible, without any air being lost due to the tight sealing, it has to go right up and through the radiator. The front radiator will cater for our charge cooling system and the rear triple pass radiator is for the new power plant (which is yet to be disclosed).

AIM Technologies

We then received this awesome care package from AIM with their PDM32 goodies. This included the module itself, which takes care of all the electrical circuits, removing the need for traditional fuse boxes and relay. A PDM32 6″ display with race icons was specced so that we can see the vital parameters such as speed, rpm, oil temperature etc. We also went for a 12 button CAN switch pad pro and a 10 channel wireless wheel pad with CAN connection and wireless receiver. A big thanks to AIM Technologies for giving us a great deal on these parts.

The next job on the huge job list is to get to work installing all these parts into the car. As you can see there’s plenty here! Our engine of choice is currently being prepared ready to be installed in the car too. Make sure you stay tuned for the next one as we disclose all the juicy details of what engine it’ll be running. You definitely won’t want to miss it!

We sent all of the suspension parts off, including the nuts and bolts, to be stripped down and blasted to make them as fresh as they could be. The results are incredible as years of grime and muck gets removed.

Our very own Andy Ford spent some time stripping back the paint in the arches ready for a fresh blast of New Formula Red.

He then stripped down the custom NSX bonnet that we’ve previously used on Tsuki, and gave it a lick of paint.

In a mission to make the car as light as we can, we enlisted the help of our good friend and fellow Tegiwa Racing driver, Ilya Krylov a.k.a Ruskiweldfab, or as we prefer to call him, the king of carbon. Having completely DIY’ed his Time Attack turbo Clio out of carbon kevlar, we gave him the task of making carbon headlight covers for us. We won’t be using the pop ups in our NSX due to the drag that it creates. We’ve now gone from the covers weighing just over 730 grams to just 170 grams each. We then had them painted to match the rest of the car. You can check out how Ilya fabricated these covers in the video below!

With the refurbished suspension components back together, Connor installed the brakes and coilovers. Yellow Speed Racing once again feature on this build like they have done for many years now on plenty of our builds. The front and rear brakes were off Tsuki so we gave them some TLC with the gloss black paint to restore them after years of hard abuse on track. YSR coilovers feature again and with the use of the external reservoirs these allow us the suspension to perform at peak levels over a longer period of time. Much needed for the 120+ minute races we’re planning on doing in this.

The full Hardrace NSX catalogue features too. The most noticeable of which are the rear toe arms. These allow us to fine-tune the toe in and out so we can get the exact geometry that we want. They’ll also provide extra stability and increased steering response too.

A set of wide carbon scoops adorn the side of the car to allow for as much air flow into the engine bay as possible.

We sent the car off to Shaun at SW Motorsport so he could fabricate a full T45 bolt-in roll cage for the car. Finished in gun metal grey, this cage will comply with strict motorsport regulations and keep the driver safe in case the worst happens.

The OEM glass windows made way for a set of lexan polycarbonate windows. These save roughly 50% compared to the original ones!

We have now sent the car off to Andy Frost @ ICEFAB for a host of custom upgrades including a new cooling pack and 4 point air jack system too. Stay tuned as we bring you updates very soon!

Now, you’ll know that Tsuki has been down plenty of avenues from endurance racing to setting blistering lap times in Time Attack. We’re going back to where it all began with this particular NSX build as we build the ultimate endurance car. This will be built in-house by our team, that have already stripped the car right down to the bare shell. As you can see from the picture below, all the parts that we won’t be using are out of the car including the C30A V6 power plant that the NSX left the factory with. We’ll be having a huge clear out of the aforementioned items on our eBay store, so make sure you keep your eyes peeled for when they get listed.

What engine will we be using?

Speaking of power plants, we’ll more than likely be utilising another Honda K-series of some description. Whilst some of the purists out there might be saying how sacrilege this is, we’ll be saving at least 100kg by using a K-Series and not to mention that parts are much easier to source as well as the tuneability that they offer!

We’ve already had the arms and sub frame vapour blasted already to return them to OE goodness. Our in-house whittler Andy Ford is currently stripping down the underseal that’s previously been on the car ready for a fresh blast of New Formula Red paint underneath and on the arches. As you can see there’s no sign of rust here, and that’s because the shell is made of aluminium, which was a drastic first in the production car realm.

What suspension will we be using?

We’ll be enlisting the help of Yellow Speed Racing as always with a set of their race proven coilover systems. As you can see this suspension system utilises external reservoirs which allows for increased oil capacity to dissipate heat, so we can operate at optimum performance over the course of a 2-hour race.

If you go to any club level race meeting in the UK, chances are you’ll see plenty of SW Motorsports roll cages. That’s why we’ll be going for SW Motorsports T45 roll cage to take care of safety and comply with regulations.

We’re sure they’ll be plenty of progress coming thick and fast in the next few weeks so make sure you stay tuned on our socials as we’ll be updating this build thread as soon as anything happens! If you want to follow this build through the images, then make sure you’re following our Flickr page too.